A force problem that seems easy but hard

A 2.00-kg aluminum block and a 6.00-kg copper block are connected by a light string over a frictionless pulley. The two blocks are allowed to move on a fixed steel block wedge (of angle 30.0) as shown in Figure P4.53. Making use of Table 4.2, determine (a) the acceleration of the two blocks and (b) the tension in the string.

My work so far:
For the aluminum block - I got T = 2a, which I cannot solve
For the copper block - I got Tx-58.8sin(30) = 6a - this is for x direction
and
Ny-58.8cos(30) = 6a - this is for y direction